Internal combustion engine



March 20, 1956 WOLF-DIETER BENSINGER ETAL INTERNAL COMBUSTION ENGINE Filed Nov. 29, 1950 United States Patent() INTERNAL coMBUsTloN ENGINE Wolf-Dieter Bensinger, Stuttgart-Untertrkheim, and Adolf F. C. Wente, Stuttgart-Bad Cannstatt, Germany, assignors to Daimler-Benz Aktiengesellschaft, Stuttgart- Unterturkheim, Germany Application November 29, 1950, Serial No. 198,096 Claims priority, application Germany December 7, 1949 7 claims. (cl. 12s- 191) This invention relates to an internal combustion engine in which the joint between cylinder casing and cylinder head is arranged slantingly with relation to the cylinder axis and in which the combustion chamber is limited in part by the piston crown and in part by the `cylinder wall and unilaterally offset from the cylinder axis.

A primary object of the invention is to provide an improved location of the valves and preferably to permit making the valves as large as possible. Another object of the invention relates to an improved shaping of the combustion chamber. A further object of the invention is to provide a convenient design of the cylinder head in combination with the oblique joint and the arrangement of the valves in the cylinder head.

One main feature of the invention accordingly resides in that the combustion chamber is formed in part by the one oblique flank of a substantially roof-shaped piston crown and in part by a recess in the cylinder casing opening towards the cylinder, one of the valves being located in the cylinder head above the combustion chamber. It is convenient in this case to provide for an approximately hemispherical shape of the combustion chamber such that its substantially plane base is formed by the valve arranged in the lower end wall of the cylinder head,` whilst the pocket-like retracted wall of the cylinder receives, for instance, a spark plug and is conveniently designed approximately cylindrically with its wall arranged in parallel relationship to the cylinder axis of the engine. The overlapping of the combustion chamber with the `cylinder periphery is preferably provided at the highest point of the combustion chamber limited by the oblique wall of the cylinder head.

According to a further feature of the invention, there is a valve located also above that portion of the piston crown which closely approaches the cylinder head.` The valves are preferably arranged perpendicularly with respect to the end wall or joint.

As a rule, it is advantageous to use the valve-located in the cylinder head above the combustion chamber as an exhaust valve, and the valve which in the upper deadcenter of the piston is substantially covered by the latter -as an intake valve. It may, however, be of advantage in certain cases to provide for an inverse arrangement of the valves.

The engine designed according to the invention is above all advantageous when used as an induction-system sparkignition engine but may be employed also, for instance, as a compression-ignition or other type of engine. The injection nozzle is arranged in this case in a similar way as the spark plug preferably in the pocket-like retracted wall of the cylinder hemispherically limiting the combustion chamber.

i The invention provides above all tl1e-following advantages:

,The area of the end wall being enlarged by its Obliquity, limiting the cylinder space and containing, for instance, the valves is still further enlarged according to the invention by thelateral projection ofthe'combustion cham- 2,738,780 Patented Mar. 20, 1956 ber laterally beyond the cylinder space, though this lateral extension of the combustion chamber beyond the cylinder periphery may be kept within moderate limits. The obliquity of the end wall or joint in particular permits the use of larger valves with the same cylinder diameter than it is possible with a joint extending normally to the cylinder axis. On the other hand the angle of inclination of the end wall and of the joint respectively formed by said end wall between the cylinder and the cylinder head may be made smaller with the valve dimensions being kept the same than with an oblique joint which does not overlap the combustion chamber formed by the recess in the cylinder casing.

The location of the exhaust valve above the combustion chamber provides as a further advantage that initial ignition occurring at the hot exhaust valve takes place at a point where this is comparatively harmless to the formed by the retracted wall actual ignition. On the other hand, the alternative arrangement ofthe intake valve above the combustion chamber provides the possibility of favorable conditions of inow, whilst simultaneously the thermal stress on the exhaust valve can be reduced owing to its being covered by the piston. According to the circumstances there may be obtained in this way in some cases a diminution of the knocking tendency.

Further particulars and advantages of the invention will be more apparent from the following description of one embodiment thereof, reference being had to the accompanying drawings, in which:

Fig. l is a vertical section through the upper portion of an internal combustion engine along the line A-B of Fig. 2 and Fig. 2 is a plan view of the end wall limiting the cylinder against the cylinder head.

In the drawings there is shown a water-cooled cylinder casing 1 in which a piston 2 is slidable. The cylinder casing has placed thereon the cylinder head 3, the joint 4 between the cylinder casing and the cylinder head extending obliquely with respect to the cylinder axis in particular such that (above all in multi-cylinder engines) the crankshaft axis and wrist pin extend in parallel and spaced relationship with the joint. The joint 4 is formed by the lower end wall or closure 5 of the cylinder head Y and constitutes at the same time the upper end wall of the cylinder space. The valves 6 and 7 are arranged normally to the joint 4 and the end wall 5 respectively, of which conveniently the (e. g. somewhat larger) valve 6 controls the inlet port and the valve 7 the outlet port. As. shown in particular in Fig. 2, the two valves are arranged opposite each other and oiset with relation to a transverse plane extending through a portion of the recess portion 9 and containing the cylinder axis, the valve 7 laterally overlapping the cylinder periphery 1 formed by the gliding surface of the. piston.

Below the valve 7 there is arranged, eccentrically with relation to the cylinder axis and overlapping the cylinder endwall 5 constitutes with the disc of the valve 7 the base of the hemisphere, whilst the hemispherical walls of the combustion chamber are in part formed by the retracted wall 9 of the engine casing and in part by the flattened out and troug 1 shaped piston crown 11. The other half 12 of the piston crown approximates in the upper deadrcenter closely the end wall 5 and the valve 6 arranged therein respectively.

In the wall 9 of the combustion chamber there is located the spark plug 13. The valves are operated, for

.. 'instance, by rocker arms (not shown in the drawing) I -shaped half 10 of the roof carried by the cylinder head. These rocker arms are actuated from a lowered camshaft by means of tappets the position of which is indicated such as at 14 and which are arranged onebeside the other in conformity with the. laterally offset position of the valves. 15 for the valve 6, for instance the intake port, issues. at

the lateral face 16 of the cylinder head whichis likewise` The valve portv inder housing having a cylinder with a substantially circularly-shaped retracted wall forming a recess therein, Va*

cylinder head on said cylinder housing, the planeY ofsepa ration between said cylinder'head andvsaid cylinder nous inglyingat an acute angle to the axis of said cylinder, said plane substantially defining an end closure' forl said cylinder, apiston reciprocable in said cylinder, .said piston having a wrist pin and a roof shaped head havingtwo sides, said wrist pin extending transversely to theroofshaped head, one of said sides closelyxapproaches; said plane when said piston is in its upper position, the other side ofsaid-piston head being curved in at least oneplane; passing through the cylinder axis and substantiallyV per-y pendicular to said wrist pin and cooperating with thepor.- tion of said end closure that is furthest from saidxwrist pin and said retracted wall to form a combustionchamf ber, a valve located in the portion of said end closure that adjoins the combustion chamber, a further valve locatedin said end closure in the portion where the closure is` closely approached by said piston, said valves'havingaxes substantially perpendicular to the plane of the endclosure,

and'said valvesbeing laterally displaced fromzea'chvother and located substantially on opposite sides ofV aplane extending throughy a portion of said recess perpendicular'. to'y the. axis of said wrist pin and parallel to the axis ofsaid cylinder.

2. An internal combustion engine as dened' inclaim 1 wherein said other side of the piston roof andsaidre-v tractedwall of the cylinderhousing definethe combustionY chamber so that it substantially hasthe form of a'. herni-V sphere, the'substantially flat diametricportion ofswhichsis' formed principally by said first-mentioned' valve;

3. Inv anfinternal combustion engine comprising a cyl-A inder housing havinga cylinder therein, a recess in'said cylinder housing opening freelyy towards said` cylinder formed in part by a retractedY wall circularly shaped' inl a plane; passing` through` said recess and perpendicular to the cylinder axis, a cylinder head formingl anvend wall for said cylinder housing, the plane of separation between said cylinder head and said cylinder housing forming an acute angle with the axis of said cylinder, a piston' reciprocableV in said cylinder, said pistonA hav ing a wrist pin and aroof-shaped head having two sides,

one side closely approaching said plane when' said fpis'ton is in its upper position, the otherA side of said piston head cooperating with the portion of said'endiwallthat* is farthest removed from said wrist pin and' forming with said recess a combustion chamber, a` rst valve.

including discrneans' located in the portion of said end wall that adjoins the combustion chamber, a secondval've. including disc means located in the portion of saidend',

wall where said piston closely approaches said planein its upper position, the'disc means of said iirst-mentioned valve extending in part beyond said cylinder; the axes of said valves lying substantially on opposite sidesi of .a

plane extending through said recess and containing that 4 longitudinal axis of said cylinder, the valve axes being substantially perpendicular to said end wall.

4. In an internal combustion engine, a cylinder housing having a cylinder therein, a recess formed by a retracted wall in said cylinder housing opening freely towards said cylinder, a substantially roof-shaped piston in said cylinder having two roof portions, a cylinder headdeiningan end'wall for said cylinder; said recess,v

one of. said root' portions of said piston, and. a portion ofsaid end wall dening a combustionY chamber, av first valve having disc means in the other roof portion of said end wall away from said combustion chamber, and a second valve having disc means in the portion of said endt wall." dening said combustion chamber, the. disc means of said second valve extending in part beyond the circumference of said cylinder, the disc means of said valves lying substantially on opposite sides of a plane extending through said recess and containing the longitudinalaxis' of said cylinder, the axes of said valves being' substantially perpendicular to said end wall, saidY one4 roof portion being substantially circularly shaped in a plane including the cylinder axis and passingk through said recess.

5. In an internal combustion engine, a cylinder housing having a cylinder therein, a cylinder head dening anend` wall for said cylinder, said end wall forming an acute angle with the cylinder axis, a piston in said cylinderhaving a wrist pin and a roof-shaped head having two sides, one side of said piston head closely approachingV saidl end'wall with said piston in its upper dead' center position, a recess in said cylinder near said end wallformed in part by a substantially circularly-shaped retractedwallof the cylinder housing, the other side of said 'piston head being` curved in a plane passing through said' recess and perpendicular to said wrist pin and forming with the part of said end wall farthest removed from said wrist pin and with said recess a combustion charnber, a 'rst valve in the portion of said end wall adjacent said one side of said piston head, a second valve in the portion of said end wall adjacent said combustion chamber, and a spark plug in said recess, said valves lying substantially on opposite sides of a plane extending through said recess and passing through the cylinder axis.

6J In an internal combustion engine, a cylinder housingv,having a cylinder therein, a cylinder head defining an end wallfor said cylider, said end wall forming an lacute angle with the cylinder axis, a piston in said cylinder having a wrist pin and a two-sided roof-shaped head, one, sideiof, said piston head closely approaching said-end wall with said piston inthe upper dead center position thereof, a recess provided in said cylinder near' `said endwall, formed in part by a retracted wall of thel cylinder housing substantially circularly shaped in a plane'. perpendicular to the cylinder axis, the' other side of` said 'piston-head being curved in a plane perpendicular to saidiwrist pin and passing through said recess and forming a' combustion chamber with the part of said end wallifarthest'removed from said wrist pin and with said recess, an inlet valve in the portion of said end wall adjacent said one side of said piston head,.an outlet valve i.the,portion.of said, end wall adjacent said combustion chamber, and aisparkvplugk in said retracted wall, said` valves lying`` substantially on opposite sides. of a plane extendingy through saidrecess and passingithrough4 the. cylinder.' axis, the radius of curvature of said circularlyshaped retracted wall being smaller than that of said cylinder.

72 Combination according to claim 6, wherein' said other side of said piston head and said recess arecurved toform aA substantially hemi-spherical combustion chamber.

(References on following page) References Cited in the le of this patent 2,282,435 UNITED STATES PATENTS gg 2,028,760 DillStl'Om Jall- 28, 1936 2,428,886 2,061,826 Bremser Nov. 24,l 1936 5 2,094,893 Jacoby OC. 5, 1937 2,126,939 Winfield Aug. 16, 1938 174,145 2,133,592 Tallb Oct. 18, 1938 247,729

6 Swaine May 12, 1942 Sanders Sept. 1S, 1942 Pescara July 10, 1945 MacPherson Oct. 14, 1947 FOREIGN PATENTS Great Britain Jan. 13, 1922 Great Britain Feb. 25, 1926 

